Comprehensive analysis of ADAMTS13 in patients with liver cirrhosis

SummaryDecreased plasma ADAMTS13 activity (ADAMTS13:AC) results in the accumulation of unusually large von Willebrand factor multimer (UL-VWFM) and the formation of platelet thrombi. It remains controversial whether or not plasma ADAMTS13:AC decreases in patients with liver cirrhosis (LC), and its relationship to clinical features has not been fully investigated. We measured ADAMTS13:AC and its related parameters in plasma in 33 patients with chronic hepatitis (CH) and in 109 patients with LC. ADAMTS13:AC decreased with increasing severity of liver disease (controls means 100%, CH 87%, Child A-LC 79%, Child B-LC 63%, and Child C-LC 31%), and showed severe deficiency (<3% of controls) in five end-stage LC. Activities measured by act-ELISA strongly correlated with those determined by the VWFM assay and ADAMTS13 antigen. Multivariate analysis showed Child-Pugh score and spleen volume independent factors contributing to ADAMTS13:AC. VWFM patterns were normal in 53% of cases, degraded in 31%, and unusually large in 16%. Patients with unusually large VWFM had the lowest ADAMTS13:AC as well as the highest Child-Pugh score, serum creatinine and blood ammonia levels. Plasma inhibitor against ADAMTS13 detected in 83% of patients with severe to moderate ADAMTS13:AC deficiency mostly showed marginal zone between 0.5 and 1.0 BU/ml. The IgG-type autoantibodies specific to plasma derived-ADAMTS13 was detected by Western blot in only five end-stage LC with severe ADAMTS13:AC deficiency. In conclusion, both plasma ADAMTS13 activity and antigen levels decreased with increasing severity of cirrhosis. An imbalance between the decreased ADAMTS13:AC and its increased substrate may reflect the predisposing state for platelet thrombi formation in patients with advanced LC.

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Ratio of von Willebrand factor antigen to ADAMTS13 activity is a useful biomarker for acute‐on‐chronic liver failure development and prognosis in patients with liver cirrhosis

Hepatology Research ◽

10.1111/hepr.13743 ◽

2021 ◽

Author(s):

Masahide Enomoto ◽

Hiroaki Takaya ◽

Tadashi Namisaki ◽

Yukihisa Fujinaga ◽

Norihisa Nishimura ◽

...

Keyword(s):

Liver Cirrhosis ◽

Liver Failure ◽

Von Willebrand Factor ◽

Chronic Liver ◽

Adamts13 Activity ◽

Chronic Liver Failure ◽

Von Willebrand Factor Antigen ◽

Von Willebrand ◽

Willebrand Factor ◽

Factor Antigen

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FRETS-VWF73 rather than CBA assay reflects ADAMTS13 proteolytic activity in acquired thrombotic thrombocytopenic purpura patients

Thrombosis and Haemostasis ◽

10.1160/th13-08-0688 ◽

2014 ◽

Vol 112 (08) ◽

pp. 297-303 ◽

Cited By ~ 13

Author(s):

Ilaria Mancini ◽

Carla Valsecchi ◽

Luca Lotta ◽

Louis Deforche ◽

Silvia Pontiggia ◽

...

Keyword(s):

Thrombotic Thrombocytopenic Purpura ◽

Proteolytic Activity ◽

Binding Activity ◽

Adamts13 Activity ◽

Flow Conditions ◽

Thrombocytopenic Purpura ◽

Severe Deficiency ◽

Adamts13 Deficiency ◽

Von Willebrand ◽

Willebrand Factor

SummaryCollagen-binding activity (CBA) and FRETS-VWF73 assays are widely adopted methods for the measurement of the plasmatic activity of ADAMTS13, the von Willebrand factor (VWF) cleaving-protease. Accurately assessing the severe deficiency of ADAMTS13 is important in the management of thrombotic thrombocytopenic purpura (TTP). However, non-concordant results between the two assays have been reported in a small but relevant percentage of TTP cases. We investigated whether CBA or FRETS-VWF73 assay reflects ADAMTS13 proteolytic activity in acquired TTP patients with non-concordant measurements. Twenty plasma samples with non-concordant ADAMTS13 activity results, <10% using FRETS-VWF73 and ≥20% using CBA, and 11 samples with concordant results, <10% using either FRETS-VWF73 and CBA assays, were analysed. FRETS-VWF73 was performed in the presence of 1.5 M urea. ADAMTS13 activities were also measured under flow conditions and the VWF multimer pattern was defined in order to verify the presence of ultra-large VWF due to ADAMTS13 deficiency. In FRETS-VWF73 assay with 1.5 M urea, ADAMTS13 activity significantly increased in roughly 50% of the samples with non-concordant results, whereas it remained undetectable in all samples with concordant measurements. Under flow conditions, all tested samples showed reduced ADAMTS13 activity. Finally, samples with non-concordant results showed a ratio of high molecular weight VWF multimers higher than normal. Our results support the use of FRETS-VWF73 over CBA assay for the assessment of ADAMTS13 severe deficiency and indicate urea as one cause of the observed differences.

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Lysine Histone-Induced Thrombocytopenia in Zebrafish Depends on Endothelial Von Willebrand Factor

Blood ◽

10.1182/blood-2018-99-117589 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 3761-3761

Author(s):

Liang Zheng ◽

X. Long Zheng

Keyword(s):

Von Willebrand Factor ◽

Fluorescent Protein ◽

Acute Infection ◽

Intraperitoneal Administration ◽

Adamts13 Activity ◽

Zebrafish Model ◽

Blood Disorder ◽

Severe Deficiency ◽

Von Willebrand ◽

Willebrand Factor

Abstract Thrombotic thrombocytopenic purpura (TTP), a potentially fatal blood disorder, is caused by severe deficiency of plasma ADAMTS13 activity, primarily resulting from acquired autoantibodies that inhibit ADAMTS13's ability to cleave von Willebrand factor (VWF). However, severe deficiency of plasma ADAMTS13 activity alone is often not sufficient to cause an acute episode of TTP; additional environmental or genetic factors may be required for the development of acute TTP. Here, we report a creation and characterization of a novel zebrafish model of TTP and use the model to identify a potential mechanistic link between an innate immunity and onset of TTP. Using CRISPR/cas9, we generated adamts13-/-,vwf-/-, and adamts13-/-vwf-/-zebrafish on a double transgenic (Fli1-eGFP/Gata1-dsRed) background in which erythrocytes, thrombocytes, and endothelial cells were uniquely labeled with an endogenously expressed fluorescent protein. Our results demonstrated that adamts13-/-zebrafish larvae (5-dpf) had an increased rate of developing occlusive thrombi in the caudal venues after FeCl3 injury; also, adamts13-/- adult zebrafish (3-4 months) exhibited ~27% reduction of their total or mature thrombocyte counts with a significantly increased number of fragmented erythrocytes; moreover, an intraperitoneal administration of a lysine-rich histone resulted in severe and more persistent thrombocytopenia with an increased mortality in adamts13-/-zebrafish than their wild-type littermate; finally, both spontaneous and histone-induced thrombocytopenia and thrombotic microangiopathy in adamts13-/-was eliminated when endothelial vwf was genetically deleted from zebrafish. Together, these results provide experimental evidences to support a mechanistic link of acute infection or inflammation to acute onset of TTP in patients lacking plasma ADAMTS13 activity. Disclosures Zheng: Alexion: Research Funding, Speakers Bureau.

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An IAP retrotransposon in the mouse ADAMTS13 gene creates ADAMTS13 variant proteins that are less effective in cleaving von Willebrand factor multimers

Blood ◽

10.1182/blood-2007-01-070953 ◽

2007 ◽

Vol 110 (3) ◽

pp. 886-893 ◽

Cited By ~ 29

Author(s):

Wenhua Zhou ◽

Eric E. Bouhassira ◽

Han-Mou Tsai

Keyword(s):

Von Willebrand Factor ◽

Full Length ◽

Carboxyl Terminus ◽

Mouse Strains ◽

Activity Levels ◽

Adamts13 Activity ◽

Severe Deficiency ◽

Type Particle ◽

Von Willebrand ◽

Willebrand Factor

AbstractSevere deficiency of ADAMTS13, a von Willebrand factor (VWF)–cleaving metalloprotease, causes thrombotic thrombocytopenic purpura. When analyzed with VWF multimers, but not with an abbreviated VWF peptide (VWF73) as the substrate, the plasma ADAMTS13 activity levels of mouse strains segregated into a high and a low group that differed by approximately 10 fold. Low ADAMTS13 activity was detected in mice containing 2 alleles of intracisternal A-type particle (IAP) retrotransposon sequence in the ADAMTS13 gene. Molecular cloning of mouse ADAMTS13 identified 2 truncated variants (IAP-a and IAP-b) in the low-activity mice. Both of the IAP variants lacked the 2 carboxyl terminus thrombospondin type 1 repeat (TSR) and CUB domains of full-length ADAMTS13. The IAP-b variant also had splicing abnormalities affecting the spacer domain sequence and had miniscule enzymatic activity. Compared with full-length ADAMTS13, the IAP-a variant was approximately one ninth as active in cleaving VWF multimers but was only slightly less active in cleaving VWF73 peptide. Recombinant human ADAMTS13 was also less effective in cleaving VWF multimers than VWF73 when the C-terminal TSR sequence was deleted. In summary, the carboxyl terminus TSR sequence is important for cleaving VWF multimers. Assay results should be interpreted with caution when peptide substrates are used for analysis of variant ADAMTS13 proteins.

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Evaluation and Clinical Application of a New Method for Detecting ADAMTS13 Activity.

Blood ◽

10.1182/blood.v114.22.2134.2134 ◽

2009 ◽

Vol 114 (22) ◽

pp. 2134-2134

Author(s):

Anyou Wang ◽

Ningzheng Dong ◽

Zhenni Ma ◽

Jingyu Zhang ◽

Jian Su ◽

...

Keyword(s):

Conflicts Of Interest ◽

Sandwich Elisa ◽

Correlation Factor ◽

Adamts13 Activity ◽

Simple Method ◽

Severe Deficiency ◽

Before And After ◽

Von Willebrand ◽

Relationship Of ◽

Willebrand Factor

Abstract Abstract 2134 Poster Board II-111 Introduction: A severe deficiency of ADAMTS13 activity contributes to the pathogenesis of thrombotic thrombocytopenic purpura (TTP). Measuring the activity of ADAMTS13 is helpful for the diagnosis of TTP and the prognostic monitor in TTP patients. Most available assays are cumbersome and costly, and not appropriate for routine laboratories. ADAMTS13 cleaves the von Willebrand factor (VWF) within the domain A2, which locates between the domains A1 and A3. Therefore, specific assays for ADAMTS13 activity could be based on the different structure of VWF before and after the cleavage. Materials and Methods: To determine the activity of ADAMTS13, a new simple method has been developed in this study. Firstly, plasma samples were exposed in denaturing condition to allow cleavage of VWF by ADAMTS13. Then, the ADAMTS13 activity was measured with two novel monoclonal antibodies (SZ-129 and SZ-125), which are specifically recognize the VWF A1 and A3 domain, respectively, by using a two-site sandwich ELISA. Comparing with a residual-collagen binding assay (R-CBA), plasma ADAMTS13 activities in 161 samples were assessed, and the inhibitory activities of ADAMTS13 autoantibodies in 24 TTP patients were determined. The relationship of these two assays was analyzed by linear correlation, and the sensitivity and specificity of the new assay was also evaluated. Results Our results showed that plasma ADAMTS13 activities determined by the new assay were consistent with those of R-CBA, the squared correlation factor was 0.9183 of the two assays, and the coefficient of variation for the new assay was 6.17%. In 23 idiopathic TTP patients, the inhibitor activities of ADAMTS13 autoantibodies were ranged from 12% to 100%, while no inhibitory activity was detected in one hereditary TTP patient. Conclusions This new and simple assay for ADAMTS13 activity could be used routinely in clinic to determine the activity of ADAMTS13. Disclosures: No relevant conflicts of interest to declare.

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Von Willebrand factor–cleaving protease (ADAMTS13) in thrombocytopenic disorders: a severely deficient activity is specific for thrombotic thrombocytopenic purpura

Blood ◽

10.1182/blood-2002-02-0344 ◽

2002 ◽

Vol 100 (2) ◽

pp. 710-713 ◽

Cited By ~ 233

Author(s):

Valentina Bianchi ◽

Rodolfo Robles ◽

Lorenzo Alberio ◽

Miha Furlan ◽

Bernhard Lämmle

Keyword(s):

Thrombotic Thrombocytopenic Purpura ◽

Von Willebrand Factor ◽

Adamts13 Activity ◽

Thrombocytopenic Purpura ◽

Heparin Induced Thrombocytopenia ◽

Severe Deficiency ◽

Uremic Syndrome ◽

Adamts13 Deficiency ◽

Von Willebrand ◽

Willebrand Factor

Abstract A severe deficiency in von Willebrand factor–cleaving protease (ADAMTS13) activity (< 5% that in normal plasma) has been observed in most patients with a diagnosis of thrombotic thrombocytopenic purpura (TTP) but not in those with a diagnosis of hemolytic uremic syndrome. However, ADAMTS13 deficiency has been claimed not to be specific for TTP, since it was observed in various thrombocytopenic and other conditions. We studied 68 patients with thrombocytopenia due to severe sepsis or septic shock (n = 17), heparin-induced thrombocytopenia (n = 16), idiopathic thrombocytopenic purpura (n = 10), or other hematologic (n = 15) or miscellaneous conditions (n = 10). Twelve of the 68 patients had subnormal levels of ADAMTS13 activity (≤ 30%), but none had less than 10%. Thus, the study showed that ADAMTS13 activity is decreased in a substantial proportion of patients with thrombocytopenia of various causes. A severe deficiency of ADAMTS13 (< 5%), identified in more than 120 patients during 1996 to 2001 in our laboratory, is specific for a thrombotic microangiopathy commonly labeled TTP.

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